Roadside refuges: Assessing the value of linear roadsides for conserving arboreal mammals in Victoria's Strathbogie ranges

Locating and protecting large continuous forest patches for traditional conservation reserves (e.g. national parks) is becoming increasingly challenging due to ongoing habitat loss and modification. Off-reserve conservation provides a means to complement existing reserves, facilitating landscape connectivity and hence, the creation of reserve networks that support species? populations. In Australia, remnant strips of native vegetation along roadsides have been retained in many agricultural landscapes. These can help support a diverse array of wildlife, including arboreal mammals, yet typically they lack formal protection. To determine the distribution, relative abundance, and diversity of arboreal mammals, including the threatened greater glider, in the Strathbogie Ranges of Victoria, I repeat spotlight surveyed 30 stratified-randomly selected 500 m roadside sites. I examined site- and landscape-level habitat factors influencing variation in arboreal mammal species among roadsides. Arboreal mammals were generally widely distributed and common throughout roadside vegetation. Excluding greater gliders, average species occupancy was 85%, ranging from 63-100%. Average species abundance was 2.4 animals per 500 m, ranging from 1.4-4.5. Greater gliders were less abundant than anticipated, present at only 13% of sites, suggesting they may have more specialised requirements than other co-occurring arboreal mammal species, and therefore the few roadsides in which they are found have substantial and underappreciated conservation importance. The relative abundance of species at the site-level appeared to be influenced by resource availability, including food (e.g. A. dealbata, E. viminalis and tree diversity) and shelter requirements (e.g. trees >20 m and symphyomyrtles). Species abundance and diversity were greater at roadsides with less surrounding forest cover and greater distance to forest patches, and a positive relationship with larger roadside areas was also evident, albeit not strong. Species diversity was positively associated with Acacia and symphyomyrtle eucalypt abundance, suggesting that roadsides with more of these plants III (resources) generally support higher species diversity. Identifying key characteristics of roadsides that support higher arboreal mammal abundance and diversity can be used to help identify ?significant? roadsides in the Strathbogie Ranges and potentially elsewhere, and guide restoration of roadside habitats too. My study highlights that although they are small in total area, linear roadsides play a vital role in supporting populations of arboreal mammals, including threatened species, and such areas need greater attention as they provide valuable opportunities for off-reserve conservation of wildlife.